JP2013-233052A discloses an inverter device arranged above a driving motor generator in electric automobiles, hybrid automobiles, and so forth. This inverter device supplies battery electrical power to the motor generator and is provided with a power module for charging a battery with regenerative electrical power from the motor generator and three alternating-current bus bars for connecting the motor generator to the power module. The three alternating-current bus bars are provided so as to project out to the outside of a housing through an opening.